Live yeast improves pigs’ resistance to heat stress through improved feeding behavior and metabolism

A recently published paper in the British Journal of Nutrition gives further insight into the benefits of the live yeast Saccharomyces cerevisiae boulardii CNCM I-1079 (LEVUCELL SB) on pig performance during heat stress. The study was conducted in partnership with the INRAE team of Etienne Labussière, David Renaudeau, and doctoral student Aira Maye Serviento. The paper detailed their trial with fattening pigs in simulated heat stress.

“Aira Maye Serviento collaborated with us for the past three years conducting her Ph.D., and I’d like to congratulate her for her hard work and thesis. Her work brings a significant contribution to our understanding of the effect of heat stress on pigs and deeper insights on the mechanisms of the probiotic yeast to mitigate it,” comments Mathieu Castex, R&D Director for Lallemand Animal Nutrition.

The benefit of LEVUCELL SB to the ability of growing pigs to cope with heat stress has already been documented, and more recent studies indicated a positive effect at the microbiota level. The present study aimed at investigating whether the live yeast had an effect on feeding behavior and energy metabolism.

• The study confirmed that heat stress significantly decreased dry matter intake and retained energy in control pigs.
• Pigs receiving live yeast supplementation had modified feeding behavior with significantly shorter inter-meal intervals and thus had higher total feed intake during heat stress.
• The researchers showed the improved resistance to heat stress was due to improved insulin sensitivity of the pigs and latent heat loss capacity after meals, allowing them to increase both their feed intake (via a higher number of meals) and their energy efficiency. As a result, protein deposition reached a higher maximum potential, which is otherwise limited in hot conditions.
• The study also showed that imposing an increased meal frequency could not replicate the positive effects of live yeast supplementation during heat stress. This is because the altered feeding behavior is not the cause, but a mere consequence, of the improved energy metabolism and thermoregulation responses of the supplemented pigs.

In conclusion, improved heat tolerance of live yeast-supplemented pigs lies in their ability to maintain the dynamic equilibrium between heat production and loss throughout the day. Live yeast S. cerevisiae boulardii CNCM I-1079 remains an interesting tool to help animals cope with the growing heat stress conditions.